Apparatus for controlling the extraction duration in a laundry treating appliance

Abstract

An apparatus for monitoring a characteristic of the motor for use in determining the duration of the extraction phase of the cycle of operation in a laundry treating appliance.

What is claimed is: 
     
         1 . A laundry treating appliance, comprising:
 a rotatable treatment chamber in which the laundry is received for treatment;   a motor coupled to and rotating the treatment chamber;   a motor torque sensor outputting a torque signal indicative of the motor torque; and   a controller having an extraction program comprising a plurality of executable instructions stored in a memory of the controller, and the controller operably coupled to the motor and receiving the torque signal such that the controller controls the motor to implement the extraction program by rotating the treatment chamber through multiple, sequentially increasing set spin speeds, which are at least a speed sufficient to satellize laundry in the treatment chamber at each of the set spin speeds, which results in a corresponding constant speed plateau where the treating chamber is rotated at a constant speed for the corresponding set spin speed to define sequentially increasing constant speed plateaus, ceasing the sequentially increasing speed plateaus when the set spin speed reaches a predetermined upper limit, monitoring the torque signal indicative of motor torque during the speed plateaus, determining from the monitoring when the time rate of change of the torque signal falls below a predetermined time rate of change threshold value, and sequential advancement from a current one of the speed plateaus to the next one of the speed plateaus is triggered when the time rate of change of the torque signal falls below the predetermined time rate of change threshold value for the current one of the speed plateaus.   
     
     
         2 . The laundry treating appliance of  claim 1  further comprising a rotatable drum defining the treatment chamber. 
     
     
         3 . The laundry treating appliance of  claim 2  wherein the drum is rotatable about at least one of a horizontal axis or vertical axis. 
     
     
         4 . The laundry treating appliance of  claim 2  wherein the drum is perforated. 
     
     
         5 . The laundry treating appliance of  claim 2  further comprising a tub in which the drum is rotatably mounted. 
     
     
         6 . The laundry treating appliance of  claim 1  further comprising a motor speed sensor outputting a speed signal indicative of the rotation speed of the motor, and wherein the controller is operably coupled to the motor and receiving the speed signal. 
     
     
         7 . The laundry treating appliance of  claim 6  wherein the controller is further configured to control the motor to implement the extraction program by monitoring the speed signal indicative of the rotational speed of the motor during the speed plateaus, determining from the monitoring when the time rate of change of the speed signal satisfies a speed threshold value and the time rate of change of the torque signal falls below the predetermined time rate of change threshold value, and sequential advancement from a current one of the speed plateaus to the next one of the speed plateaus is triggered when the speed threshold value is satisfied and the time rate of change of the torque signal falls below the predetermined time rate of change threshold value. 
     
     
         8 . The laundry treating appliance of  claim 7  wherein the motor speed sensor is part of the motor. 
     
     
         9 . The laundry treating appliance of  claim 1  wherein the motor torque sensor is part of the motor. 
     
     
         10 . The laundry treating appliance of  claim 1  wherein the motor torque sensor comprises a motor current sensor or a motor voltage sensor. 
     
     
         11 . The laundry treating appliance of  claim 1  wherein the controller is further configured to control the motor to implement the extraction program by determining a leveling of a motor characteristic indicative of motor torque when the time rate of change of the torque signal falls below the predetermined time rate of change threshold value. 
     
     
         12 . The laundry treating appliance of  claim 11  wherein the controller is further configured to control the motor to implement the extraction program by monitoring the leveling of the motor characteristic when a magnitude of the motor characteristic satisfies a motor characteristic threshold value. 
     
     
         13 . The laundry treating appliance of  claim 1  wherein the controller is further configured to control the motor to implement the extraction program by accelerating the rotation of the treating chamber between each of the speed plateaus. 
     
     
         14 . A laundry treating appliance, comprising:
 a rotatable treatment chamber in which the laundry is received for treatment;   a motor coupled to and rotating the treatment chamber;   a moisture sensor outputting a moisture signal indicative of the residual liquid retained in the laundry;   a motor torque sensor outputting a torque signal indicative of the motor torque; and   a controller having an extraction program comprising a plurality of executable instructions stored in a memory of the controller, and the controller operably coupled to the motor and receiving the moisture signal and the torque signal such that the controller controls the motor to implement the extraction program by rotating the treatment chamber through multiple, sequentially increasing set spin speeds, which are at least a speed sufficient to satellize laundry in the treatment chamber at each of the set spin speeds, which results in a corresponding constant speed plateau where the treating chamber is rotated at a constant speed for the corresponding set spin speed to define sequentially increasing constant speed plateaus, ceasing the sequentially increasing speed plateaus when the moisture signal indicative of the residual liquid retained in laundry satisfies a residual liquid threshold, monitoring the torque signal indicative of motor torque during the speed plateaus, determining from the monitoring when the time rate of change of the torque signal falls below a predetermined time rate of change threshold value, and sequential advancement from a current one of the speed plateaus to the next one of the speed plateaus is triggered when the time rate of change of the torque signal falls below the predetermined time rate of change threshold value for the current one of the speed plateaus.   
     
     
         15 . The laundry treating appliance of  claim 1  wherein the motor torque sensor comprises a motor current sensor or a motor voltage sensor. 
     
     
         16 . The laundry treating appliance of  claim 1  wherein the controller is further configured to control the motor to implement the extraction program by determining a leveling of a motor characteristic indicative of motor torque when the time rate of change of the torque signal falls below the predetermined time rate of change threshold value. 
     
     
         17 . The laundry treating appliance of  claim 16  wherein the controller is further configured to control the motor to implement the extraction program by monitoring the leveling of the motor characteristic when a magnitude of the motor characteristic satisfies a motor characteristic threshold value. 
     
     
         18 . A laundry treating appliance, comprising:
 a rotatable treatment chamber in which the laundry is received for treatment;   a motor coupled to and rotating the treatment chamber;   a motor torque sensor outputting a torque signal indicative of the motor torque; and   a controller having an extraction program comprising a plurality of executable instructions stored in a memory of the controller, and the controller operably coupled to the motor and receiving the torque signal such that the controller controls the motor to implement the extraction program by rotating the treatment chamber through multiple, sequentially increasing set spin speeds, which are at least a speed sufficient to satellize laundry in the treatment chamber at each of the set spin speeds, which results in a corresponding constant speed plateau where the treating chamber is rotated at a constant speed for the corresponding set spin speed to define sequentially increasing constant speed plateaus, ceasing the sequentially increasing speed plateaus after a predetermined number of advancements, monitoring the torque signal indicative of motor torque during the speed plateaus, determining from the monitoring when the time rate of change of the torque signal falls below a predetermined time rate of change threshold value, and sequential advancement from a current one of the speed plateaus to the next one of the speed plateaus is triggered when the time rate of change of the torque signal falls below the predetermined time rate of change threshold value for the current one of the speed plateaus.   
     
     
         19 . The laundry treating appliance of  claim 18  wherein the motor torque sensor comprises a motor current sensor or a motor voltage sensor. 
     
     
         20 . The laundry treating appliance of  claim 18  wherein the controller is further configured to control the motor to implement the extraction program by determining a leveling of a motor characteristic indicative of motor torque when the time rate of change of the torque signal falls below the predetermined time rate of change threshold value.